fbintf/client/FBEvents.pas

(*
 *  Firebird Interface (fbintf). The fbintf components provide a set of
 *  Pascal language bindings for the Firebird API. Although predominantly
 *  a new development they include source code taken from IBX and may be
 *  considered a derived product. This software thus also includes the copyright
 *  notice and license conditions from IBX.
 *
 *  Except for those parts dervied from IBX, contents of this file are subject
 *  to the Initial Developer's Public License Version 1.0 (the "License"); you
 *  may not use this file except in compliance with the License. You may obtain a
 *  copy of the License here:
 *
 *    http://www.firebirdsql.org/index.php?op=doc&id=idpl
 *
 *  Software distributed under the License is distributed on an "AS
 *  IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 *  implied. See the License for the specific language governing rights
 *  and limitations under the License.
 *
 *  The Initial Developer of the Original Code is Tony Whyman.
 *
 *  The Original Code is (C) 2016 Tony Whyman, MWA Software
 *  (http://www.mwasoftware.co.uk).
 *
 *  All Rights Reserved.
 *
 *  Contributor(s): ______________________________________.
 *
*)
{************************************************************************}
{                                                                        }
{       Borland Delphi Visual Component Library                          }
{       InterBase Express core components                                }
{                                                                        }
{       Copyright (c) 1998-2000 Inprise Corporation                      }
{                                                                        }
{    InterBase Express is based in part on the product                   }
{    Free IB Components, written by Gregory H. Deatz for                 }
{    Hoagland, Longo, Moran, Dunst & Doukas Company.                     }
{    Free IB Components is used under license.                           }
{                                                                        }
{    The contents of this file are subject to the InterBase              }
{    Public License Version 1.0 (the "License"); you may not             }
{    use this file except in compliance with the License. You            }
{    may obtain a copy of the License at http://www.Inprise.com/IPL.html }
{    Software distributed under the License is distributed on            }
{    an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either              }
{    express or implied. See the License for the specific language       }
{    governing rights and limitations under the License.                 }
{    The Original Code was created by InterBase Software Corporation     }
{       and its successors.                                              }
{    Portions created by Inprise Corporation are Copyright (C) Inprise   }
{       Corporation. All Rights Reserved.                                }
{    Contributor(s): Jeff Overcash                                       }
{                                                                        }
{    IBX For Lazarus (Firebird Express)                                  }
{    Contributor: Tony Whyman, MWA Software http://www.mwasoftware.co.uk }
{    Portions created by MWA Software are copyright McCallum Whyman      }
{    Associates Ltd 2011 - 2015                                                }
{                                                                        }
{************************************************************************}
unit FBEvents;

{$IFDEF FPC}
{$mode objfpc}{$H+}
{$interfaces COM}
{$ENDIF}

interface

uses
  Classes, SysUtils, IB, FBClientAPI, syncobjs, FBActivityMonitor;

type

  { TFBEvents }

  TFBEvents = class(TActivityReporter)
  private
    FEvents: TStringList;
    FAttachment: IAttachment;
  protected
    FEventBuffer: PChar;
    FEventBufferLen: integer;
    FResultBuffer: PChar;
    FEventHandler: TEventHandler;
    FCriticalSection: TCriticalSection;
    FInWaitState: boolean;
    procedure CreateEventBlock;
    procedure CancelEvents(Force: boolean = false); virtual;
    procedure EventSignaled;
    function GetIEvents: IEvents; virtual; abstract;
  public
    constructor Create(DBAttachment: IAttachment; aMonitor: IActivityMonitor; Events: TStrings);
    destructor Destroy; override;

    {IEvents}
    procedure GetEvents(EventNames: TStrings);
    procedure SetEvents(EventNames: TStrings); overload;
    procedure SetEvents(Event: string); overload;
    procedure Cancel;
    function ExtractEventCounts: TEventCounts;
    function GetAttachment: IAttachment;
  end;


implementation

uses FBMessages, IBExternals;

const
  MaxEvents = 15;

{ TFBEvents }

procedure TFBEvents.CreateEventBlock;
var
  i: integer;
  EventNames: array of PChar;
begin
  with FirebirdClientAPI do
  begin
    if FEventBuffer <> nil then
      isc_free( FEventBuffer);
    FEventBuffer := nil;
    if FResultBuffer <> nil then
      isc_free( FResultBuffer);
    FResultBuffer := nil;

    setlength(EventNames,MaxEvents);
    try
      for i := 0 to FEvents.Count-1 do
        EventNames[i] := PChar(FEvents[i]);

      FEventBufferlen := isc_event_block(@FEventBuffer,@FResultBuffer,
                          FEvents.Count,
                          EventNames[0],EventNames[1],EventNames[2],
                          EventNames[3],EventNames[4],EventNames[5],
                          EventNames[6],EventNames[7],EventNames[8],
                          EventNames[9],EventNames[10],EventNames[11],
                          EventNames[12],EventNames[13],EventNames[14]
                          );
    finally
      SetLength(EventNames,0)
    end;
  end;
end;

procedure TFBEvents.CancelEvents(Force: boolean);
begin
  FEventHandler := nil;
end;

procedure TFBEvents.EventSignaled;
var Handler: TEventHandler;
begin
  FCriticalSection.Enter;
  try
    if not FInWaitState then Exit;
    FInWaitState := false;
    if assigned(FEventHandler)  then
    begin
      Handler := FEventHandler;
      FEventHandler := nil;
    end;
  finally
    FCriticalSection.Leave
  end;
  Handler(GetIEvents);
end;

constructor TFBEvents.Create(DBAttachment: IAttachment;
  aMonitor: IActivityMonitor; Events: TStrings);
begin
  inherited Create(aMonitor);
  FAttachment := DBAttachment;
  if Events.Count > MaxEvents then
    IBError(ibxeMaximumEvents, [nil]);

  FCriticalSection := TCriticalSection.Create;
  FEvents := TStringList.Create;
  FEvents.Assign(Events);
  CreateEventBlock;
end;

destructor TFBEvents.Destroy;
begin
  if assigned(FCriticalSection) then FCriticalSection.Free;
  if assigned(FEvents) then FEvents.Free;
  with FirebirdClientAPI do
  begin
    if FEventBuffer <> nil then
      isc_free( FEventBuffer);
    if FResultBuffer <> nil then
      isc_free( FResultBuffer);
  end;
  inherited Destroy;
end;

procedure TFBEvents.GetEvents(EventNames: TStrings);
begin
  EventNames.Assign(FEvents)
end;

procedure TFBEvents.SetEvents(EventNames: TStrings);
begin
  if EventNames.Text <> FEvents.Text then
  begin
    Cancel;
    FEvents.Assign(EventNames);
    CreateEventBlock;
  end;
end;

procedure TFBEvents.SetEvents(Event: string);
var S: TStringList;
begin
  S := TStringList.Create;
  try
    S.Add(Event);
    SetEvents(S);
  finally
    S.Free;
  end;
end;

procedure TFBEvents.Cancel;
begin
  if assigned(FEventHandler) then
    CancelEvents;
end;

function TFBEvents.ExtractEventCounts: TEventCounts;
var EventCountList, P: PISC_LONG;
    i: integer;
    j: integer;
begin
  SetLength(Result,0);
  if FResultBuffer = nil then Exit;

  GetMem(EventCountList,sizeof(ISC_LONG)*FEvents.Count);
  try
    with FirebirdClientAPI do
       isc_event_counts( EventCountList, FEventBufferLen, FEventBuffer, FResultBuffer);
    j := 0;
    P := EventCountList;
    for i := 0 to FEvents.Count - 1 do
    begin
      if EventCountList[i] > 0 then
      begin
        Inc(j);
        SetLength(Result,j);
        Result[j-1].EventName := FEvents[i];
        Result[j-1].Count := P^;
        Inc(P);
      end;
    end;
  finally
    FreeMem(EventCountList);
  end;
end;

function TFBEvents.GetAttachment: IAttachment;
begin
  Result := FAttachment;
end;

end.

Revision:	45
Committed:	Tue Dec 6 10:33:46 2016 UTC (8 years ago) by tony
Content type:	text/x-pascal
Original Path:	*ibx/trunk/fbintf/client/FBEvents.pas*
File size:	8262 byte(s)
Log Message:	Committing updates for Release R2-0-0
#	User	Rev	Content
1	tony	45	(*
2			* Firebird Interface (fbintf). The fbintf components provide a set of
3			* Pascal language bindings for the Firebird API. Although predominantly
4			* a new development they include source code taken from IBX and may be
5			* considered a derived product. This software thus also includes the copyright
6			* notice and license conditions from IBX.
7			*
8			* Except for those parts dervied from IBX, contents of this file are subject
9			* to the Initial Developer's Public License Version 1.0 (the "License"); you
10			* may not use this file except in compliance with the License. You may obtain a
11			* copy of the License here:
12			*
13			* http://www.firebirdsql.org/index.php?op=doc&id=idpl
14			*
15			* Software distributed under the License is distributed on an "AS
16			* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
17			* implied. See the License for the specific language governing rights
18			* and limitations under the License.
19			*
20			* The Initial Developer of the Original Code is Tony Whyman.
21			*
22			* The Original Code is (C) 2016 Tony Whyman, MWA Software
23			* (http://www.mwasoftware.co.uk).
24			*
25			* All Rights Reserved.
26			*
27			* Contributor(s): ______________________________________.
28			*
29			*)
30			{************************************************************************}
31			{ }
32			{ Borland Delphi Visual Component Library }
33			{ InterBase Express core components }
34			{ }
35			{ Copyright (c) 1998-2000 Inprise Corporation }
36			{ }
37			{ InterBase Express is based in part on the product }
38			{ Free IB Components, written by Gregory H. Deatz for }
39			{ Hoagland, Longo, Moran, Dunst & Doukas Company. }
40			{ Free IB Components is used under license. }
41			{ }
42			{ The contents of this file are subject to the InterBase }
43			{ Public License Version 1.0 (the "License"); you may not }
44			{ use this file except in compliance with the License. You }
45			{ may obtain a copy of the License at http://www.Inprise.com/IPL.html }
46			{ Software distributed under the License is distributed on }
47			{ an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either }
48			{ express or implied. See the License for the specific language }
49			{ governing rights and limitations under the License. }
50			{ The Original Code was created by InterBase Software Corporation }
51			{ and its successors. }
52			{ Portions created by Inprise Corporation are Copyright (C) Inprise }
53			{ Corporation. All Rights Reserved. }
54			{ Contributor(s): Jeff Overcash }
55			{ }
56			{ IBX For Lazarus (Firebird Express) }
57			{ Contributor: Tony Whyman, MWA Software http://www.mwasoftware.co.uk }
58			{ Portions created by MWA Software are copyright McCallum Whyman }
59			{ Associates Ltd 2011 - 2015 }
60			{ }
61			{************************************************************************}
62			unit FBEvents;
63
64			{$IFDEF FPC}
65			{$mode objfpc}{$H+}
66			{$interfaces COM}
67			{$ENDIF}
68
69			interface
70
71			uses
72			Classes, SysUtils, IB, FBClientAPI, syncobjs, FBActivityMonitor;
73
74			type
75
76			{ TFBEvents }
77
78			TFBEvents = class(TActivityReporter)
79			private
80			FEvents: TStringList;
81			FAttachment: IAttachment;
82			protected
83			FEventBuffer: PChar;
84			FEventBufferLen: integer;
85			FResultBuffer: PChar;
86			FEventHandler: TEventHandler;
87			FCriticalSection: TCriticalSection;
88			FInWaitState: boolean;
89			procedure CreateEventBlock;
90			procedure CancelEvents(Force: boolean = false); virtual;
91			procedure EventSignaled;
92			function GetIEvents: IEvents; virtual; abstract;
93			public
94			constructor Create(DBAttachment: IAttachment; aMonitor: IActivityMonitor; Events: TStrings);
95			destructor Destroy; override;
96
97			{IEvents}
98			procedure GetEvents(EventNames: TStrings);
99			procedure SetEvents(EventNames: TStrings); overload;
100			procedure SetEvents(Event: string); overload;
101			procedure Cancel;
102			function ExtractEventCounts: TEventCounts;
103			function GetAttachment: IAttachment;
104			end;
105
106
107			implementation
108
109			uses FBMessages, IBExternals;
110
111			const
112			MaxEvents = 15;
113
114			{ TFBEvents }
115
116			procedure TFBEvents.CreateEventBlock;
117			var
118			i: integer;
119			EventNames: array of PChar;
120			begin
121			with FirebirdClientAPI do
122			begin
123			if FEventBuffer <> nil then
124			isc_free( FEventBuffer);
125			FEventBuffer := nil;
126			if FResultBuffer <> nil then
127			isc_free( FResultBuffer);
128			FResultBuffer := nil;
129
130			setlength(EventNames,MaxEvents);
131			try
132			for i := 0 to FEvents.Count-1 do
133			EventNames[i] := PChar(FEvents[i]);
134
135			FEventBufferlen := isc_event_block(@FEventBuffer,@FResultBuffer,
136			FEvents.Count,
137			EventNames[0],EventNames[1],EventNames[2],
138			EventNames[3],EventNames[4],EventNames[5],
139			EventNames[6],EventNames[7],EventNames[8],
140			EventNames[9],EventNames[10],EventNames[11],
141			EventNames[12],EventNames[13],EventNames[14]
142			);
143			finally
144			SetLength(EventNames,0)
145			end;
146			end;
147			end;
148
149			procedure TFBEvents.CancelEvents(Force: boolean);
150			begin
151			FEventHandler := nil;
152			end;
153
154			procedure TFBEvents.EventSignaled;
155			var Handler: TEventHandler;
156			begin
157			FCriticalSection.Enter;
158			try
159			if not FInWaitState then Exit;
160			FInWaitState := false;
161			if assigned(FEventHandler) then
162			begin
163			Handler := FEventHandler;
164			FEventHandler := nil;
165			end;
166			finally
167			FCriticalSection.Leave
168			end;
169			Handler(GetIEvents);
170			end;
171
172			constructor TFBEvents.Create(DBAttachment: IAttachment;
173			aMonitor: IActivityMonitor; Events: TStrings);
174			begin
175			inherited Create(aMonitor);
176			FAttachment := DBAttachment;
177			if Events.Count > MaxEvents then
178			IBError(ibxeMaximumEvents, [nil]);
179
180			FCriticalSection := TCriticalSection.Create;
181			FEvents := TStringList.Create;
182			FEvents.Assign(Events);
183			CreateEventBlock;
184			end;
185
186			destructor TFBEvents.Destroy;
187			begin
188			if assigned(FCriticalSection) then FCriticalSection.Free;
189			if assigned(FEvents) then FEvents.Free;
190			with FirebirdClientAPI do
191			begin
192			if FEventBuffer <> nil then
193			isc_free( FEventBuffer);
194			if FResultBuffer <> nil then
195			isc_free( FResultBuffer);
196			end;
197			inherited Destroy;
198			end;
199
200			procedure TFBEvents.GetEvents(EventNames: TStrings);
201			begin
202			EventNames.Assign(FEvents)
203			end;
204
205			procedure TFBEvents.SetEvents(EventNames: TStrings);
206			begin
207			if EventNames.Text <> FEvents.Text then
208			begin
209			Cancel;
210			FEvents.Assign(EventNames);
211			CreateEventBlock;
212			end;
213			end;
214
215			procedure TFBEvents.SetEvents(Event: string);
216			var S: TStringList;
217			begin
218			S := TStringList.Create;
219			try
220			S.Add(Event);
221			SetEvents(S);
222			finally
223			S.Free;
224			end;
225			end;
226
227			procedure TFBEvents.Cancel;
228			begin
229			if assigned(FEventHandler) then
230			CancelEvents;
231			end;
232
233			function TFBEvents.ExtractEventCounts: TEventCounts;
234			var EventCountList, P: PISC_LONG;
235			i: integer;
236			j: integer;
237			begin
238			SetLength(Result,0);
239			if FResultBuffer = nil then Exit;
240
241			GetMem(EventCountList,sizeof(ISC_LONG)*FEvents.Count);
242			try
243			with FirebirdClientAPI do
244			isc_event_counts( EventCountList, FEventBufferLen, FEventBuffer, FResultBuffer);
245			j := 0;
246			P := EventCountList;
247			for i := 0 to FEvents.Count - 1 do
248			begin
249			if EventCountList[i] > 0 then
250			begin
251			Inc(j);
252			SetLength(Result,j);
253			Result[j-1].EventName := FEvents[i];
254			Result[j-1].Count := P^;
255			Inc(P);
256			end;
257			end;
258			finally
259			FreeMem(EventCountList);
260			end;
261			end;
262
263			function TFBEvents.GetAttachment: IAttachment;
264			begin
265			Result := FAttachment;
266			end;
267
268			end.
269